SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15aeb686647e5708e47aaed4a305ca604dc37587b0efa02b98ef18398df7734b' 
  AND token = 'aHm1xt1KPrwfImEfL6CaFgSzmPM1EZwfTmd7/KgTVfk=' 
  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"
    }
  }
}