SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49c75b6a9988b122cf8d4aced5fce535ba15bcecf5fe4d53847fe73e8731394b' 
  AND token = 'tuZ8Ftfl5Wb1yFp1TCT14+N+a/yk4DncuoPHhxyL6+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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