SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '666e665c856641e7e25675438f50734eab2741a59aa5f5cb34a5d39aa8f59770' 
  AND token = 'ZAVD1349EnhHALt7kVLRYqQKVgJ6X3qiGW7ybFvwrzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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