SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e524f08fda1c7058be529a4c8eb0b08fadb5aad79f5870efd044e36824a959a7' 
  AND token = 'kUvMznAqo8OVYc9F5utn2+PEJBuESmnkf2zLzHNfhCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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