SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c97fafc678148451e13a97e61cbe01e64224a3fe6fd0b1d5c0a06d92101f8a2' 
  AND token = 'dCfNkr9gRsZl0T8FwpqZlou82Di5XOdlFMR+37PZtYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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