SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed0f749523b54327024015d3d3ef0947f82717f3a30c349738a185af09f39ef0' 
  AND token = 'JoKvlJ0TqXGfxO7kkdaWytw/IA+aYTs5lsIZAwvyFss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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