SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9cb2e650cc00a54953fc2ae8d27eb6e8e44a2cae03fc7d32668077c5a7da709' 
  AND token = 'YgJXaDadHXkLZ49P9xiAntKxKB7XqJjX0oTOrstSpkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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