SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f88885ad833e6a11b81d6b916ddee34b81bb6fd90d931b06c917f8a7fe54490d' 
  AND token = 'tHz9IjxYfOTEmik4lwcqhpq0BF9to7gFWzsy2cUDEeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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