SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9841b595666db607553db0928d99134deea1ffeae8e0d39e4b26b6039060e947' 
  AND token = 'PDqr5NqUj2yYLM2oRXg8xF3Ja7MpqwtSbAqmflDjYXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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