SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88c6ad6b2c72e9d5159af6093bf863f746f3cd16eafcabe88c84f0cd97398d32' 
  AND token = 'YjUTGgCO+7ZvOAXkahf2oi3yRxF7E+0Bywpq4jUReF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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