SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddc2ed92bb568cf4f859d6aad131cba464ba4d80736f8b4dbb884bdecc349500' 
  AND token = 'ATFidk+HA+0B0ftZvENdtDvPjzSXK2/a1JeVgdRCblo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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