SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a99149ba7c3dd294ba82ed5872b63f562e4724a7d50f6bc17367811df06f862' 
  AND token = 'WenmWEIUpGbDsnvcwluAc08vUOPG7s8vcoBOgGb1KAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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