SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87000257a52643c2a641c30d4b9b96ac04cea2566af564aa5fb07a8b1b4f8709' 
  AND token = 'WEYzx/nIHGT1wcFfpNz5nVewRS9/A+LkuK1OA2x9jCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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