SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c07a5db5638b656e327328ed98c268511588d7af34fd0295300c73fa220f773a' 
  AND token = 'NHKqZWESHskhJYClzsqRdbwGvtTSmJ5RbSrPJYL9+7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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