SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c926c9ab35c0afe11f8d8a3bad7470d9cf623ecc108b9ba45bd9144a9298767' 
  AND token = 'yr1nlznu/73DMvTtjiYBQWWDvf5LWQTh3yADwIpqBbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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