SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4794e107a3d60b19dbedf1e8c430c221cc8875f63e91c7c97a8c80755df49d3' 
  AND token = 't7xrkpYGbgh+liPUgO1BMTFWwGEkiJgjQZcKveSpX2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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