SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5327e374a324d9582dc9a10354026e3970aa95a47fa3cb93fae4334c0d3bbdf1' 
  AND token = 'bJ9R52nX4WyyHASra0ptrtZkrQVkOeabegzCfmXLtZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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