SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8933ce56706d43370abe3ac4337c2ad048a9b1f822fcf15223740c592881472c' 
  AND token = 'uHUh8jlbshLOqiIRxUv2UzsOrweMGCGMI20GD7pHMo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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