SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5de258462be31cccda3fc375c5b877a5cd02dd719173fbe1d32d793807291016' 
  AND token = 'YBL/Yq7Q9fQ5VI7S6ubdiWi9iQ1kSi3vAQYYBZOxjEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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