SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '542d2e1d13e10afca425a58138154c38ed63ba13fcf6769311a82a49d104a099' 
  AND token = 'sbtWZGxVhYdgA4Whe2F1jzpvOUw7Ih7oBUQGOXGOMlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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