SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e1a8fd4b55597bd469db14da723aef3efe41eb69cdce95c2f13b2799ec7c480' 
  AND token = 'oSc92B3uheEQjMrfPXlq3oWP4WqqRY0XV9eJFqhj0HE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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