SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa600fe7847dc1d774d34a472974cf6ca02ecaa617a5a15dc8ffb19fa0a4665d' 
  AND token = '1k+49/h4QGYo2H5fTGpHK6Sb2mHv7i3V79x5bqLibZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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