SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa4632f266160156fc27528611160c52dbb80d672c7064823b19206342f83ddf' 
  AND token = 'IVjnAgsBuu8fJS0Pkti4lVWeMmGKagMQlIccjx1So1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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