SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26be36a96d4f308979a094e26f6d331cda115af141a9cea36952449da8abe966' 
  AND token = 'Km0AEXxnnymaHjTubKFUT+PpIj7Uv16JrMav7xPGGn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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