SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd23f1a90903c623bc56e1f3829326c8a5e746ccccdda6054d805e682f01c84d0' 
  AND token = 'IpYxkQVkRYGHLLXfL9pubBSxE1vlVFznbmZ4JymenCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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