SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd02e1f140ebe296b1d962d422bf20a537f2aec70e3ffbc1b3f533fa6e793ad1' 
  AND token = 'MhX7im/INPoBSjw3xORtDSgLCqr8mzVAmmVKkc+SlVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00087

JSON explain

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