SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a560c4f0cfdf98f2161600df06dfc20b45eaaf860ead10ab76e584f5397d402c' 
  AND token = 'liO45OLSTDWoiZ+TYy/df4TOvrWdwEtuDt8qI+bMUNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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