SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b83022803b27996c98a454fdae82b36e3abcd8f4b305df784c12b6db33d52fb6' 
  AND token = 'NbwmtYI0j12dfA4maegsSWJT3kRGxEiIjBt0ucJhAXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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