SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7084a855a7ca46be32f9440438f1304687a6d16e0be303bc764bf0cfa12f9ba3' 
  AND token = 'XYq+MlaXS6QZ7pYe2AMyxqnSQ9lEa473c/OZkH7DB6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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