SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4297f0bf24d53ce073bac3fefa7f9fceadaa56e90062e23f41deeb54f52f8ce0' 
  AND token = 'WN3pUMhXU7y695Qz6IzcBRi9+6MK2pH68YLpGtruu3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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