SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '567bcf1bdf94b127e8c495b38469bfc04ba11bb2165f13bd06a1f988c4b84abe' 
  AND token = '28Wsp+8EQPz6TYSJ3TeVGJeQ95FLnRuenkim8mHSGL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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