SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8335799c7efd74a1b4c4924d0f3fe5888e16e09f5fcf6ed98a4cffad27342980' 
  AND token = 'h4J/rFQ0Ykn8sQIP7m1d0XZq4QFJqKZzxU4UniscXrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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