SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36614b7d3bb0c998194c2ce9ba093762de5dead676b302dfc88109fbca056bd1' 
  AND token = 'Wb4V40JTnD2T20axHueKnsEYvi8nu8ItZKv0Q1kdXmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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