SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4e6131bbdb642da0c80b872123aca9f1fe2043ae9ac80551ffde63f976b4c59' 
  AND token = 'WRbrYf74dE4EECq7v9dr+nI0R8eJPkddSQkNaLuoKuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}