SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc3194cae38b433e1bbc31bf4318a4de2fe45f4e3863252865cf0592400b3753' 
  AND token = 'wMvKL5nC0lMq4rPKKeOhzpPK7aajBTYd59tQnZ5mdxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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