SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bd2e872986caa437396abbeed6f79a701983a8280b64d38d3eafeea22f43e73' 
  AND token = 'AROYplrvPyNoF00wey0K8Ujf0Ke1d+a+6zbWFqYnPRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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