SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3effef16411a052bc1a44e99463c87cfa84105d945d90485c30d0161f33e7dae' 
  AND token = 'gR3ZMLk9aDDrwsbrKakFc2qWUlHprXbkkJOk1L3AL7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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