SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fdc26068bc97590eba2477fd9760a12158234554cddbdfa60921080f83ce181' 
  AND token = '8/aiOfIUF8fckC+F9RLV4KTiljr0SPO5gjfMUZe7dDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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