SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6405da9c29526faf93f8f3f7bf3b20db73532e05ef805dad2d985ec9f429600e' 
  AND token = 'bHM9+zXO3nvy80RgPkT0PC4m142e2JzRF/RmczkbQmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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