SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f042735a35c562db394ce9755236f754c6cc18b028bd912e551a5394acbd8c35' 
  AND token = 'UdvKREnK+81HmxoPRwOVhATmPkp/4PdHaP475K7lL4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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