SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1706d49009faede40d6fe64e41dc30f06e5c7a41f59ba160190c83fc498d5c1' 
  AND token = 'mr0qJwkW3uSi3+7/P9gpI3Or9yVChrOaNMQ2YUtttgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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