SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17a7f8686d4351ea838c91e2ad49260119e5c48d359c860f8be887c0c4808768' 
  AND token = 'EQlG/aKNXYs8H0LcccMUGa3r2C9cz4QcIXBthEb+b+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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