SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df65b85f0bc762727024f683031049f7314925eef8f625b448176c00a24578c9' 
  AND token = 'tjEt3fENPDSjX2CuUqqpUJs5wYP5m7knYyzVe9vwrDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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