SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66dfea11e88e1abe209d9f67b1641d156223db3d6a54ffea9a33fdf680a6b071' 
  AND token = 'QtrX+oNQHCbJcjh+HLJEsHiYZy/V4ZV2WhUrDQBqUnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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