SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da87450e3e075a06462b2b09a3a96153af169d96481113e504cf30086418bc9a' 
  AND token = 'dkDnYJU1lslx9IovCFdrRPkk6xIWtZZyUOfP+ldKdHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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