SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '184971f508d829dba1d73cfbe7285d7a7fca6acc4736a74ab5efff56272410e1' 
  AND token = 'KPixYIhRUklol84aNr9kaSWWTFrj2NTt5XMUZNPcQRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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