SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '750452edc94d1ac8f8b156a45dc26ad6963e8b2bb0bdf5e22133093630979094' 
  AND token = 'NIkzEwIYxKHJgETUYU0yxyZyS9q+GsqxtwVK/H9mvnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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