SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87f5ad7865ebab1947c0e74a129ecfe1b2800bf8472b6be6d6ae220e509067e5' 
  AND token = 'JXRnNt7UtYlinu+qt2yeCXUeLhjtcEF+PZb7Bnqo0nA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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