SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45ae6371da5606e2f245f1efe8caa23413f5d53d8334fa279950645ede1278cf' 
  AND token = 'ztp8hycduF6Y2GpuLCcRzxrQCiASppPYX2/MbMQgQVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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