SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cadc727ce6832c6e3238fd7e4933a85c931051d0e3f179105eadd830fd7dcc0' 
  AND token = 'HTNVHdmEnTebWAb2HfuFKvDq/3WYGZrLwuMSY0VwbKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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