SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '736f09ed43811c98c538aaeaf8660f9275d748566ab1df1e937e45f9e5bdd65c' 
  AND token = 'VSQ4BwaQhRFGNY4gFYqIjRPGHbq6r01rtgSrmK5hpQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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