SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd66cd18b05390794ac8f681c586e5d8f93fcf0d022d569592a221122d5009464' 
  AND token = 'N9rzeXt9d4V9KLMxrYngYgMGE6jS6fz8m7mmSyII/FQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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