SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2af8284d86c44dd6ac7b4732b05a195f9842ff58cd6f06fd590525ff5a8e01c5' 
  AND token = 'QcZiBJ5thBv1KVM1i5I3yXmhmkaOR4D2N9t6WZSg5ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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