SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20d47fb031d71cbc285bc120ac8ad993326bffb8aa1490b6605852d2a7dd47cd' 
  AND token = '9Q9bIEWgtVmLJHnU1lGbButOMRb8M1QjfatA/sgeA+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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