SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f6cb57731061b3664b0a82ff66d204893627ae195610c2fd51db6c6f618e211' 
  AND token = 'HufhPun6C8Nq+JWal1ryRNF+MThJpLkcAG0J+POMnJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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