SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '05a3096b2e3ad12cc9e4a293d25d643783caf5df0a680cbc5171cf915e5955ab' 
  AND token = '5S5FEE9ce+YULB9ubbLGOYceucaD6VyUhkR10b0JoMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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