SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '810fe87dbef6aaf66445384280003350d7950d3693e8dcffa47551fd6d4a25c2' 
  AND token = 'oVAJLvulqVwNGTRtKK+Y4xX+Rh/w5va5oBd/G8vBunc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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