SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb8f877a06313bab0921d72166908a09fd0b98c54756954f6ed93e4cf9f448f7' 
  AND token = 'oVOzyw3bQxL04lZGI+4H/gcjyfRLECCfjLf3ZBzODDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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