SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f48fa1c263ff57c5c29bfa37212f058a17f3774c3c2fc84ea9db78214a91fdb' 
  AND token = 'm/q+W/DYbTyXzl8rpuMJT8BxWsvBJignykDoH0vu578=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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