SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f2fd579883b151a148e88323aec0eb6599de3beaec9200de30048395d2427c3' 
  AND token = 'Zy/ieiFLJ5ctSxT5CqS6UUi690JW+4fGpnlqGMRbmRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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