SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1529487770fea241d05c22bad733d1c06384052f4594b152cadcba51f3522dd' 
  AND token = 'JQrexQYVVbw3WudrbQAutx7xRtuFlePb0Xq3sJ5eeJ8=' 
  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"
    }
  }
}