SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2b7999e8f837fa6654f61ecfab1a9edc15ae06a2fd024913267e8603efd0da6' 
  AND token = 'Nm+casKgVO69At+Sq8VbUk+huCxT09nnzwjDJGP/DAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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