SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c579ea097ebfa1150c5cfb961ebd60eb7dae3a9962539f2b1423daa05994c61a' 
  AND token = '34yv7F4S1TukaJPUI88aDH8Of5nlOJbgzpp+5HBo+lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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