SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71fc0c340e858085c9b3df522a3eb5c54bf177bf82cb5c7e9edf3fc9374d5999' 
  AND token = 'kCFnvBW58gwZKY+uoyG29YaoznWTG6o6yroTIqsuhCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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