SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e44bc243482d3b857cde9e474e086a0bfb9094f0ad3f14665c98b73cc271de1' 
  AND token = '9ny/6FmSSZOFOLPtqAw8cQUMFJdlK1nyYBTToJkMGKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}