SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c61e693d06bd7dbdcde65790ac67f557f1e4b098776c821ddff33614403f4b8' 
  AND token = 'I/xZLEv7q6OwxEEM/F++qrZQr5KGFSug88qar/XZ0hw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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