SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '924fc303b499751e05246c093d53a51abd199d7b20a0581a23fd01f43be9ed6b' 
  AND token = 'XA1w+SHqhq1sVHmU+J6WOxG/McxEIwRCukDIxB9qpqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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