SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dcfe6e95379c6350b58fbd32b6fd78efaf31a9c4ec797374cadcde8779b1593' 
  AND token = 'P5gq4pvoV2XTSXTHQCALhU1PXoYObWO+KOmD72QksLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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