SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae6390329f7a904f2050f4339ed9c32b486667d7b32115087caf73aa579974d2' 
  AND token = '14hkh1TSSjpFK7Din+B/nbPzYi2gWnyKJucsZcQW45k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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