SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d1084120cd3b7a59b8cf782e8f1a9747a63a99c35f4697c94c05057334d0c52' 
  AND token = 'dVjf2iYC7hNvpEhhrmFQIwTB4iabDzyOZ5Dj/gtClE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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