SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e37ddc7335f609fd912e3c492c4f5ffee67d44c918ab8bf0f9b8f7d8b423654a' 
  AND token = 'XXwTSfmoA93AifJ+YcCGiJqm7DoSzeGiBlXh7DLZHXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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