SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9c61611866cabdbde4f5ff4817af45f4169b6d415845eb21ba491369cb3e9c9' 
  AND token = 'MPYIgk9htvXxxMt0aRrVkedRw6wwbgmrhlncyzMMRSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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