SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a35aff52a2ac5dab86e39a22f191dd1b1fae38d6a11a8f7cea5b4054bab7f24' 
  AND token = 'HRAQh/cyQqJtWZbFvYYE1AKSZMQ+oitjGVOPdX1BJTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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