SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8469d9e3ee1feeaa1e0d57200c4ddbf0b8873b2af78361e4a2448450b6186d3' 
  AND token = 'V73x8JjCvwg/jW9mLX12rffq0jhkoGBQ88+bzVaii2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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