SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff58f2c5d38b476f39f175a5e58d68a5c4187269df5dbb2073a0c65d88b97c09' 
  AND token = 'IDIcYcJVmPOk98IQnRxLs5+UA1MbdNF3iJUng/QQwos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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