SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a113f16960bfaf80294ebebd9d45b6482c7457f3d212cce3c1d64de9aa82201b' 
  AND token = '4BRYPFkIupope99A0YiRq87LsIvsSSqXw20pqRroOOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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