SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2847c4474fe112499fd6c4512c5640237de1e95d7c186cd7df94d7346e25d221' 
  AND token = 'QznWM0vsCGccUfgH3gTJrzYjVYpNXfxvowPzuqfjrQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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