SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48a64c3306d61347bf0e7db656627c3dc598eaacdce99b462faf757f198e7147' 
  AND token = 'fZfLHJwZxc+borokHMESOZd6qv1fRW6IZWqA1lr9FGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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