SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '205d810bb78864b681ffbd374d64ae1875d743627f9ad0f1c819e071f7ec452b' 
  AND token = 'FxpYqhV1TJFqUNwFy1HtkL7nb96bdqDbLKHKXpuI/AU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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