SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd546f94faa0b0a91aa9a29d9699414d016b6144dabf9141da4f70cda3db01109' 
  AND token = 'I3VBOgeGrd34ucoscFOPeDktlsK73TutrbmMTwoOkVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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