SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '602d846756806d5df28405c30cf4b23878ccdf2064ccc2d64de9a0a49c81c000' 
  AND token = 'TkZ8G7GzZPPTqwKhKFVyO47TufHNgEHmChoM8TO2wTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}