SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '817880ff3ea783c00fd8d7a7462c37d2046ae8f77b30baee4735dfb2865ac9b7' 
  AND token = 'XaYQhbNNGw62w98BWniz4Fwgp0LGfbX4Vn25UPXVw+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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