SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b8147d763adca7c45043ec03875fec407c8b0cdc2b34aff29d416dcf98797d1' 
  AND token = 'pG6cx+1OhlHElF8/7RsPViOw/MQrLicXIJr9ccAUjMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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