SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30b2b8504575867124bd3b89716eecb05d0712f475f6a8b74c45474afbc51deb' 
  AND token = 'dyxwnEwEgnrN47x9RNh5Vs1ZxFPwpMhe9sJD2ITGm+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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