SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '818adef586b2ed06ce25716339e9e4ddb5ba456f612458dd2f2021ff1365cbed' 
  AND token = 'n/vplwGTgVu3g3G2ftPBHL0kVYzPchawl8DJ+BFkPog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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