SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0236efa4c5054d9e90a7c864086aeffa316eeb1108af82f99cf6c38290af12d5' 
  AND token = '2mLCH4HXcRG1QKTudG0SPpidKpLYUiJwMgv3eWu9ads=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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