Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6a5dff4de706b08a72a513a0da99bdd0bdcf1afd9a7f3601acf4dabc5d30a7f' 
  AND token = 'Y1Oe2TJ0LPV8kyAKPb2Y678xj3JKi9UaE/Gz0bkf1Is=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}