SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65ab1bb026a91015e8afedcb9851a5366658975cbcecaa064021514b6ac491f1' 
  AND token = 'tUBVz1eWzTzYUUlcsnVkGlhqte6Do51SU6QEzENt4Rg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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