SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aafd4b0ebe77328f702897ba89aa4373495d9841b440b890039421871fb38d36' 
  AND token = 'zxaHLDSIM2PFNjKRJtHbJ69D1RTqPH3S85Bj0DZ1ArU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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