SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0feadb447c70b944fd7112a2fdb3598a31dae79d24af5919ad472cee5ee89a4' 
  AND token = 'Dk6Wi3C8MfH33LdTb3E+8GtmboaVAxSeTjiSajXuFpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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