SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4d2fa6710de4c4d8ac6d4aa31ef9b61027955c640ec65bd47a892a6b1f98804' 
  AND token = 'chIWtiwyQcB5wEHD/WbNvWG8UMI8mSWo/guqTOR0oHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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