SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c832620d1c5f9ae70050859e1cbbfc5340712c443740ba56f2729fb060218e1c' 
  AND token = 'WWxZoNTKWYwXLJmt2O16U+ZhJhRgEvSMinWrr0oU4fY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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