SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bb97a46b840916851ac99bce3c2daa37b1e4da7eec23616c327cfdef1c8f636' 
  AND token = 'R12VtEDoxtZPVOqloBrne8Qj+v6jwVguunTHY7eGpyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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