SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '665b03bad475f0061e69769d1680edde5f6cf3eca64c96026304696a6513f1fb' 
  AND token = 'ljo4rdvzT6u2pUYedkiXdQTONFeBZLX+CeYMeEajEHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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