SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '135c9434825dc4ee9efe03fc781872cfe3c3ab3c2c9183e1c06f4c535500b53f' 
  AND token = 'xPbgEltLy49IdpWHOg9OgasdULKD8e7TBU/y8DW7vmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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